1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * Definitions for the IP module. 7 * 8 * Version: @(#)ip.h 1.0.2 05/07/93 9 * 10 * Authors: Ross Biro 11 * Fred N. van Kempen, <[email protected]> 12 * Alan Cox, <[email protected]> 13 * 14 * Changes: 15 * Mike McLagan : Routing by source 16 * 17 * This program is free software; you can redistribute it and/or 18 * modify it under the terms of the GNU General Public License 19 * as published by the Free Software Foundation; either version 20 * 2 of the License, or (at your option) any later version. 21 */ 22 #ifndef _IP_H 23 #define _IP_H 24 25 #include <linux/types.h> 26 #include <linux/ip.h> 27 #include <linux/in.h> 28 #include <linux/skbuff.h> 29 30 #include <net/inet_sock.h> 31 #include <net/snmp.h> 32 #include <net/flow.h> 33 34 struct sock; 35 36 struct inet_skb_parm { 37 struct ip_options opt; /* Compiled IP options */ 38 unsigned char flags; 39 40 #define IPSKB_FORWARDED 1 41 #define IPSKB_XFRM_TUNNEL_SIZE 2 42 #define IPSKB_XFRM_TRANSFORMED 4 43 #define IPSKB_FRAG_COMPLETE 8 44 #define IPSKB_REROUTED 16 45 46 u16 frag_max_size; 47 }; 48 49 static inline unsigned int ip_hdrlen(const struct sk_buff *skb) 50 { 51 return ip_hdr(skb)->ihl * 4; 52 } 53 54 struct ipcm_cookie { 55 __be32 addr; 56 int oif; 57 struct ip_options_rcu *opt; 58 __u8 tx_flags; 59 }; 60 61 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb)) 62 63 struct ip_ra_chain { 64 struct ip_ra_chain __rcu *next; 65 struct sock *sk; 66 union { 67 void (*destructor)(struct sock *); 68 struct sock *saved_sk; 69 }; 70 struct rcu_head rcu; 71 }; 72 73 extern struct ip_ra_chain __rcu *ip_ra_chain; 74 75 /* IP flags. */ 76 #define IP_CE 0x8000 /* Flag: "Congestion" */ 77 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */ 78 #define IP_MF 0x2000 /* Flag: "More Fragments" */ 79 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */ 80 81 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */ 82 83 struct msghdr; 84 struct net_device; 85 struct packet_type; 86 struct rtable; 87 struct sockaddr; 88 89 int igmp_mc_proc_init(void); 90 91 /* 92 * Functions provided by ip.c 93 */ 94 95 int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, 96 __be32 saddr, __be32 daddr, 97 struct ip_options_rcu *opt); 98 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, 99 struct net_device *orig_dev); 100 int ip_local_deliver(struct sk_buff *skb); 101 int ip_mr_input(struct sk_buff *skb); 102 int ip_output(struct sk_buff *skb); 103 int ip_mc_output(struct sk_buff *skb); 104 int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)); 105 int ip_do_nat(struct sk_buff *skb); 106 void ip_send_check(struct iphdr *ip); 107 int __ip_local_out(struct sk_buff *skb); 108 int ip_local_out(struct sk_buff *skb); 109 int ip_queue_xmit(struct sk_buff *skb, struct flowi *fl); 110 void ip_init(void); 111 int ip_append_data(struct sock *sk, struct flowi4 *fl4, 112 int getfrag(void *from, char *to, int offset, int len, 113 int odd, struct sk_buff *skb), 114 void *from, int len, int protolen, 115 struct ipcm_cookie *ipc, 116 struct rtable **rt, 117 unsigned int flags); 118 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, 119 struct sk_buff *skb); 120 ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, 121 int offset, size_t size, int flags); 122 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4, 123 struct sk_buff_head *queue, 124 struct inet_cork *cork); 125 int ip_send_skb(struct net *net, struct sk_buff *skb); 126 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4); 127 void ip_flush_pending_frames(struct sock *sk); 128 struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4, 129 int getfrag(void *from, char *to, int offset, 130 int len, int odd, struct sk_buff *skb), 131 void *from, int length, int transhdrlen, 132 struct ipcm_cookie *ipc, struct rtable **rtp, 133 unsigned int flags); 134 135 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4) 136 { 137 return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base); 138 } 139 140 /* datagram.c */ 141 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); 142 143 void ip4_datagram_release_cb(struct sock *sk); 144 145 struct ip_reply_arg { 146 struct kvec iov[1]; 147 int flags; 148 __wsum csum; 149 int csumoffset; /* u16 offset of csum in iov[0].iov_base */ 150 /* -1 if not needed */ 151 int bound_dev_if; 152 u8 tos; 153 }; 154 155 #define IP_REPLY_ARG_NOSRCCHECK 1 156 157 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg) 158 { 159 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0; 160 } 161 162 void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, __be32 daddr, 163 __be32 saddr, const struct ip_reply_arg *arg, 164 unsigned int len); 165 166 struct ipv4_config { 167 int log_martians; 168 int no_pmtu_disc; 169 }; 170 171 extern struct ipv4_config ipv4_config; 172 #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field) 173 #define IP_INC_STATS_BH(net, field) SNMP_INC_STATS64_BH((net)->mib.ip_statistics, field) 174 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val) 175 #define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS64_BH((net)->mib.ip_statistics, field, val) 176 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val) 177 #define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS64_BH((net)->mib.ip_statistics, field, val) 178 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field) 179 #define NET_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.net_statistics, field) 180 #define NET_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->mib.net_statistics, field) 181 #define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd) 182 #define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd) 183 184 unsigned long snmp_fold_field(void __percpu *mib[], int offt); 185 #if BITS_PER_LONG==32 186 u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t sync_off); 187 #else 188 static inline u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_off) 189 { 190 return snmp_fold_field(mib, offt); 191 } 192 #endif 193 int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align); 194 195 static inline void snmp_mib_free(void __percpu *ptr[SNMP_ARRAY_SZ]) 196 { 197 int i; 198 199 BUG_ON(ptr == NULL); 200 for (i = 0; i < SNMP_ARRAY_SZ; i++) { 201 free_percpu(ptr[i]); 202 ptr[i] = NULL; 203 } 204 } 205 206 extern struct local_ports { 207 seqlock_t lock; 208 int range[2]; 209 } sysctl_local_ports; 210 void inet_get_local_port_range(int *low, int *high); 211 212 extern unsigned long *sysctl_local_reserved_ports; 213 static inline int inet_is_reserved_local_port(int port) 214 { 215 return test_bit(port, sysctl_local_reserved_ports); 216 } 217 218 extern int sysctl_ip_nonlocal_bind; 219 220 /* From inetpeer.c */ 221 extern int inet_peer_threshold; 222 extern int inet_peer_minttl; 223 extern int inet_peer_maxttl; 224 225 /* From ip_input.c */ 226 extern int sysctl_ip_early_demux; 227 228 /* From ip_output.c */ 229 extern int sysctl_ip_dynaddr; 230 231 void ipfrag_init(void); 232 233 void ip_static_sysctl_init(void); 234 235 static inline bool ip_is_fragment(const struct iphdr *iph) 236 { 237 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0; 238 } 239 240 #ifdef CONFIG_INET 241 #include <net/dst.h> 242 243 /* The function in 2.2 was invalid, producing wrong result for 244 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 245 static inline 246 int ip_decrease_ttl(struct iphdr *iph) 247 { 248 u32 check = (__force u32)iph->check; 249 check += (__force u32)htons(0x0100); 250 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 251 return --iph->ttl; 252 } 253 254 static inline 255 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst) 256 { 257 return inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO || 258 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT && 259 !(dst_metric_locked(dst, RTAX_MTU))); 260 } 261 262 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more); 263 264 static inline void ip_select_ident(struct sk_buff *skb, struct dst_entry *dst, struct sock *sk) 265 { 266 struct iphdr *iph = ip_hdr(skb); 267 268 if ((iph->frag_off & htons(IP_DF)) && !skb->local_df) { 269 /* This is only to work around buggy Windows95/2000 270 * VJ compression implementations. If the ID field 271 * does not change, they drop every other packet in 272 * a TCP stream using header compression. 273 */ 274 iph->id = (sk && inet_sk(sk)->inet_daddr) ? 275 htons(inet_sk(sk)->inet_id++) : 0; 276 } else 277 __ip_select_ident(iph, dst, 0); 278 } 279 280 static inline void ip_select_ident_more(struct sk_buff *skb, struct dst_entry *dst, struct sock *sk, int more) 281 { 282 struct iphdr *iph = ip_hdr(skb); 283 284 if ((iph->frag_off & htons(IP_DF)) && !skb->local_df) { 285 if (sk && inet_sk(sk)->inet_daddr) { 286 iph->id = htons(inet_sk(sk)->inet_id); 287 inet_sk(sk)->inet_id += 1 + more; 288 } else 289 iph->id = 0; 290 } else 291 __ip_select_ident(iph, dst, more); 292 } 293 294 /* 295 * Map a multicast IP onto multicast MAC for type ethernet. 296 */ 297 298 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 299 { 300 __u32 addr=ntohl(naddr); 301 buf[0]=0x01; 302 buf[1]=0x00; 303 buf[2]=0x5e; 304 buf[5]=addr&0xFF; 305 addr>>=8; 306 buf[4]=addr&0xFF; 307 addr>>=8; 308 buf[3]=addr&0x7F; 309 } 310 311 /* 312 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 313 * Leave P_Key as 0 to be filled in by driver. 314 */ 315 316 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 317 { 318 __u32 addr; 319 unsigned char scope = broadcast[5] & 0xF; 320 321 buf[0] = 0; /* Reserved */ 322 buf[1] = 0xff; /* Multicast QPN */ 323 buf[2] = 0xff; 324 buf[3] = 0xff; 325 addr = ntohl(naddr); 326 buf[4] = 0xff; 327 buf[5] = 0x10 | scope; /* scope from broadcast address */ 328 buf[6] = 0x40; /* IPv4 signature */ 329 buf[7] = 0x1b; 330 buf[8] = broadcast[8]; /* P_Key */ 331 buf[9] = broadcast[9]; 332 buf[10] = 0; 333 buf[11] = 0; 334 buf[12] = 0; 335 buf[13] = 0; 336 buf[14] = 0; 337 buf[15] = 0; 338 buf[19] = addr & 0xff; 339 addr >>= 8; 340 buf[18] = addr & 0xff; 341 addr >>= 8; 342 buf[17] = addr & 0xff; 343 addr >>= 8; 344 buf[16] = addr & 0x0f; 345 } 346 347 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 348 { 349 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0) 350 memcpy(buf, broadcast, 4); 351 else 352 memcpy(buf, &naddr, sizeof(naddr)); 353 } 354 355 #if IS_ENABLED(CONFIG_IPV6) 356 #include <linux/ipv6.h> 357 #endif 358 359 static __inline__ void inet_reset_saddr(struct sock *sk) 360 { 361 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0; 362 #if IS_ENABLED(CONFIG_IPV6) 363 if (sk->sk_family == PF_INET6) { 364 struct ipv6_pinfo *np = inet6_sk(sk); 365 366 memset(&np->saddr, 0, sizeof(np->saddr)); 367 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr)); 368 } 369 #endif 370 } 371 372 #endif 373 374 static inline int sk_mc_loop(struct sock *sk) 375 { 376 if (!sk) 377 return 1; 378 switch (sk->sk_family) { 379 case AF_INET: 380 return inet_sk(sk)->mc_loop; 381 #if IS_ENABLED(CONFIG_IPV6) 382 case AF_INET6: 383 return inet6_sk(sk)->mc_loop; 384 #endif 385 } 386 WARN_ON(1); 387 return 1; 388 } 389 390 bool ip_call_ra_chain(struct sk_buff *skb); 391 392 /* 393 * Functions provided by ip_fragment.c 394 */ 395 396 enum ip_defrag_users { 397 IP_DEFRAG_LOCAL_DELIVER, 398 IP_DEFRAG_CALL_RA_CHAIN, 399 IP_DEFRAG_CONNTRACK_IN, 400 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX, 401 IP_DEFRAG_CONNTRACK_OUT, 402 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX, 403 IP_DEFRAG_CONNTRACK_BRIDGE_IN, 404 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX, 405 IP_DEFRAG_VS_IN, 406 IP_DEFRAG_VS_OUT, 407 IP_DEFRAG_VS_FWD, 408 IP_DEFRAG_AF_PACKET, 409 IP_DEFRAG_MACVLAN, 410 }; 411 412 int ip_defrag(struct sk_buff *skb, u32 user); 413 #ifdef CONFIG_INET 414 struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user); 415 #else 416 static inline struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user) 417 { 418 return skb; 419 } 420 #endif 421 int ip_frag_mem(struct net *net); 422 int ip_frag_nqueues(struct net *net); 423 424 /* 425 * Functions provided by ip_forward.c 426 */ 427 428 int ip_forward(struct sk_buff *skb); 429 430 /* 431 * Functions provided by ip_options.c 432 */ 433 434 void ip_options_build(struct sk_buff *skb, struct ip_options *opt, 435 __be32 daddr, struct rtable *rt, int is_frag); 436 int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb); 437 void ip_options_fragment(struct sk_buff *skb); 438 int ip_options_compile(struct net *net, struct ip_options *opt, 439 struct sk_buff *skb); 440 int ip_options_get(struct net *net, struct ip_options_rcu **optp, 441 unsigned char *data, int optlen); 442 int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp, 443 unsigned char __user *data, int optlen); 444 void ip_options_undo(struct ip_options *opt); 445 void ip_forward_options(struct sk_buff *skb); 446 int ip_options_rcv_srr(struct sk_buff *skb); 447 448 /* 449 * Functions provided by ip_sockglue.c 450 */ 451 452 void ipv4_pktinfo_prepare(struct sk_buff *skb); 453 void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb); 454 int ip_cmsg_send(struct net *net, struct msghdr *msg, struct ipcm_cookie *ipc); 455 int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, 456 unsigned int optlen); 457 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, 458 int __user *optlen); 459 int compat_ip_setsockopt(struct sock *sk, int level, int optname, 460 char __user *optval, unsigned int optlen); 461 int compat_ip_getsockopt(struct sock *sk, int level, int optname, 462 char __user *optval, int __user *optlen); 463 int ip_ra_control(struct sock *sk, unsigned char on, 464 void (*destructor)(struct sock *)); 465 466 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len); 467 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port, 468 u32 info, u8 *payload); 469 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 470 u32 info); 471 472 #ifdef CONFIG_PROC_FS 473 int ip_misc_proc_init(void); 474 #endif 475 476 #endif /* _IP_H */ 477